Copying apparatus



Sept. 13, 1966 P. H. COUTURE 3,272,668

COPYING APPARATUS Filed Sept. 4, 1964 2 i. a w

w J zJ 14 Q/ 5 i 2km my INVFNTOR. fmzlfl wage??? [V A i United StatesPatent "'ce 3,272,068 COPYING APPARATUS Paul H. Couture, Shrewsbury,Mass, assignor to Dean:-

son Manufacturing Company, Framingham, Mass, a corporation of Nevada.

Filed Sept. 4, 1964, Ser. No. 394,574 1 Claim. (CI. 8824) This inventionrelates to apparatus for reproducing a record and particularly toapparatus for forming an electrostatic image on photoconductive paper orthe like by projection printing.

Objects of the invention are to provide copymg apparatus which is simpleand economical to produce, which is compact, which reproduces a recorduniform-1y throughout its entire area, which corrects for lenses havingdeficient coverage, and which is quickly and easily adjustable.

This invention involves a printer comprising a chamber having a recordwindow to receive a record sheet, and a print window to receive a sheetof photographic material, with a lens between the two windows to focusthe record sheet on the photographic sheet, the chamber and windowshaving corresponding rectangular shapes, in com bination with means forilluminating the record sheet including a light source in each of thefour corners of the chamber opposite the record window, the sides of thechamber being reflective, and a reflector behind each light source todirect light to the aforseaid sides. Preferably the reflectors directthe light predominantly to the corners of the record sheet, thereby toilluminate the corners more than the central portion of the recordsheet, and a baffle is mounted in front of each light source to preventlight from being reflected directly from the record window to the lens.

For the purpose of illustration a typical embodiment of the invention isshown in the accompanying drawing in which FIG. 1 is a vertical sectionof the apparatus;

FIG. 2 is a section on line 22 of FIG. 1;

FIG. 3 is an enlarged side view of one of the lamp assemblies; and

FIG. 4 is a plan view of the record window showing the unevenillumination which this invention eliminates substantially.

The particular embodiment of the invention chosen for the purpose ofillustration comprises a casing having two chambers 1 and 2 with apartition 3 therebetween. In the top of chamber 1 is a record window 4covered by a transparent plate 5 and a cover 6, and at the side of thechamber 2 is a print window 7 behind which a strip 8 of photoconductivematerial may be fed over rollers 9 and 11. Mounted in the partition 3 isa projection lens 12 for projecting a record in window 4 to the printwindow 7, the projected light being reflected by a mirror 13.

According to this invention lamps 14, 15, 16 and 17 are mounted onbrackets 18 in each of the four corners of the chamber 1 opposite therecord window 4. Each of these lamps is preferably of the well-knownprojection type, having a concentrated filament 19 and a built-inreflector 21 for reflecting light away from the corner in which the lampis mounted. In front of each lamp is a baffle 22 for preventing lightfrom being reflected directly from the transparent plate 5 to the lenswithout being reflected from one of the side walls 23, 24, 25 and 26 ofchamber 1 which are made reflective in any suitable way. The reflectorsshould be specular, that is, mirror-like surfaces, and not diflusereflectors like painted surfaces. If shiny aluminum foil is used itshould be stretched to lie 3,272,068 Patented Sept. 13, 1966 flat. Asshown in FIG. 1 the axes of the beam from each lamp is directedapproximately parallel with the adjacent side wall, the axes of lamps 14and 17 extending along wall 26 and the axes of lamps 15 and 16 extendingalong wall 24. Thus the axes of the beams from lamps 14 and 15 intersectwall 25 and the axes of the beams from lamps 16 and 17 intersect thewall 23. Owing to divergence each beam spreads over a considerablesurface of the reflective sides so that the illumination of the recordwindow is approximately uniform. For example, light from lamp 15 isreflected strongly from walls 24 and 25, less strongly from wall 26 andnot at all from wall 23. By aiming the beams toward the corners ofchamber 1 as aforesaid, the corners of the record window may beilluminated somewhat more than the central portion, the illuminationgradually decreasing toward the center, thereby to compensate for usuallens deficiencies.

As shown in FIG. 3 the baffles 22 may be adjustably mounted on supports27 which are hinged at 28 to swing to the dotted-line position 22' tofacilitate adjustment and replacement of the lamps, the supports beingheld in upright position by spring detents 29. The baffles are adjustedto prevent specular reflections from entering the print window, but mayallow as much as about twentyfive percent of the light to shine directlyon the windows at their corners in order to obtain increasedillumination at the corners as aforesaid. Inasmuch as the baflles tendto cast shadows on the window 4 and to get evenness of illumination, theedges of the shadows should be difluse. This may be accomplished byplacing the bafl'les close to the lamps or making the edges of thebaflies sawtoothed, as indicated at 30 in FIG. 2, or both.

According to this invention each baflle has a wing 20 on the side nextto the adjacent wall 23, 24, 25 or 26 of the chamber 1 to screen eachlamp from its adjacent wall. Without these wings the illumination of thewindow 4 is not entirely uniform, eliptical bright spots 31 and 32appearing as shown in FIG. 4. By adding wings 21) these spots aresubstantially eliminated.

It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents which fall Within the scope of the appended claim.

I claim:

For printing a sheet of photographic material from a record sheet, aprinter comprising a chamber having a record window to receive a recordsheet, a print window to receive a sheet of photographic material, alens between the two windows to focus the record sheet on thephotographic sheet, said chamber and windows having correspondingrectangular shapes, means for illuminating the record sheet including alight source in each of the four corners of said chamber opposite therecord window, a baflle in front of each light source to prevent lightfrom reflected directly from the record window to the lens, the sides ofsaid chamber being reflective, and a reflector behind each light source,each reflector being directed toward an opposite side of said chamberadjacent the record window, characterized in that each baflle has a wingon the side next to the adjacent wall of said chamber to screen eachlamp from its adjacent wall.

NORTON ANSHER, Primary Examiner. R. WINTERCORN, Assistant Examiner.

